Single action push to connect conduit fitting

ABSTRACT

A single action push to connect fitting for conduit such as tube or pipe. The fitting includes a first fitting component and a second fitting component that are joined or assembled together to form a fitting assembly. The fitting assembly includes a conduit seal device and a conduit retaining device. A conduit may be manually or otherwise inserted into the assembled fitting assembly with a single axial movement and be retained and sealed without need for further action or movement of the fitting components.

RELATED APPLICATION

The present application is a continuation application of U.S. Ser. No.14/520,616, filed Oct. 22, 2014, titled SINGLE ACTION PUSH TO CONNECTCONDUIT FITTING, which claims the benefit of pending U.S. ProvisionalPatent Application Ser. No. 61/895,043 filed on Oct. 24, 2013 for SINGLEACTION PUSH TO CONNECT CONDUIT FITTING, the entire disclosure of whichis fully incorporated herein by reference.

TECHNICAL FIELD OF THE DISCLOSURE

The inventions relate generally to fittings for conduits such as tubeand pipe. More particularly, the inventions relate to fittings thatprovide single action push to connect operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric end view of an exemplary embodiment of a fittingassembly with a conduit fully inserted,

FIG. 2 is the fitting assembly of claim 1 in longitudinal section,

FIG. 3 is an exploded isometric of the fitting assembly of FIG. 1including the conduit,

FIG. 4 is an embodiment of a first fitting component subassembly thatmay be used in the embodiment of FIGS. 1-3 in longitudinal section,

FIG. 5 is an embodiment of a second fitting component subassembly thatmay be used in the embodiment of FIGS. 1-3 in longitudinal section,

FIG. 6 is the fitting assembly of FIG. 2 shown in longitudinal sectionprior to insertion of the conduit C into the fitting assembly,

FIG. 7 is the fitting assembly of FIG. 2 shown in longitudinal sectionwith partial insertion of the conduit C into the fitting assembly,

FIG. 8 is another embodiment of a fitting assembly in longitudinalsection,

FIG. 9 is an exploded isometric of the fitting assembly of FIG. 8including the conduit.

SUMMARY OF THE EXEMPLARY EMBODIMENTS

A first inventive concept described herein is a fitting assembly forconduit, for example tube or pipe, in which a single action on theconduit can be used to achieve a fluid tight seal and retention of theconduit without need for subsequent action or motion. In an embodiment,a conduit can optionally be hand held or otherwise inserted into a firstend of the fitting assembly so as to engage a seal device and a conduitgripping member with a single action on the conduit to achieve a fluidtight seal and retention of the conduit by the conduit gripping member.No subsequent action is needed such as rotation, tightening or clampingof the fitting components. This embodiment may also be referred toherein as a single action push to connect fitting. Additionalembodiments are described herein.

A second inventive concept described herein is a fitting assembly forconduit such as tube or pipe in which a single action on the conduit canbe used to achieve a fluid tight seal and retention of the conduitwithout need for subsequent action or motion. In an embodiment, thefitting assembly may include a first fitting component or subassemblyand a second fitting component or subassembly. The first fittingcomponent and the second fitting component can be joined or assembledtogether to form a fitting assembly, and the assembled fitting allowsfor a single action on the conduit to be used to achieve a fluid tightseal and retention of the conduit. Additional embodiments are describedherein.

In another embodiment, a first fitting component or subassemblycomprises a seal device that can be used to seal the first fittingcomponent and the conduit against fluid pressure. A second fittingcomponent or subassembly comprises a retainer that grips the conduit,for example, against fluid pressure, when the conduit is inserted intothe second fitting component subassembly. The first fitting componentand the second fitting component are adapted to be joined together toform a single action push to connect fitting assembly. Additionalembodiments are described herein.

In another embodiment, a first fitting component or subassemblycomprises a seal device that can be used to seal the first fittingcomponent and the conduit against fluid pressure. A second fittingcomponent or subassembly comprises a retainer that grips the conduitagainst fluid pressure when the conduit is inserted into the secondfitting component subassembly. The first fitting component and thesecond fitting component are adapted to be joined together to form asingle action push to connect fitting assembly, wherein fluid pressurein the conduit increases gripping force applied by the retainer againstthe conduit. Additional embodiments are described herein.

These and additional aspects and embodiments of the inventions will beunderstood by those skilled in the art from the following detaileddescription of the exemplary embodiments in view of the accompanyingdrawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Herein, the terms fitting and fitting assembly are used interchangeably.In various exemplary embodiments, a fitting assembly structure as taughtherein is separately claimed as an invention without requiring theconduit to be part of the fitting assembly, and further withoutrequiring that the various parts be in a fully assembled condition (suchas may be the case, for example, of the assembly parts being shippedfrom a manufacturer or distributor.) In at least one embodiment, afitting assembly includes a first fitting component or subassemblyhaving a seal device and a second fitting component or subassemblyhaving a retainer. In any of the embodiments described herein, theconduit does not require treatment or modification from stock condition,although optionally such may be done if needed in particularapplications. For example, it is common for the conduit end to be cutsubstantially perpendicular to the conduit longitudinal axis anddeburred as needed, but even these common steps are optional and notrequired to achieve conduit grip and fluid tight seal. By stockcondition is meant that the conduit may be a conventional hollow rightcylinder having a cylindrical inner surface that may be exposed to fluid(for example, liquid, gas or other flowable material) contained by theconduit, and a cylindrical outer surface, with a wall thickness definedas the difference between the inner diameter and the outer diameter ofthe conduit. The conduit may be made of any material, is preferablymetal, and more preferably is a stainless steel alloy, but theinventions are not limited to these exemplary materials and otheralternative materials may be used as needed for particular applications.Although traditional hollow cylindrical conduits are preferred, otherconduit shapes and geometry may alternatively be used for either theouter wall or inner wall or both walls of the conduit. The word conduitherein refers to traditional tube and pipe but also includes otherhollow fluid carrying structures that might be referred to by anotherword other than tube or pipe.

With reference to FIGS. 1-3, an embodiment of a fitting assembly 10 isrepresented. The fitting assembly 10 provides for or allows singleaction push to connect operation. By single action is meant that aconduit C, and in particular the end portion C1 of the conduit end C,can be inserted into the fitting assembly 10 with a single dimensionalor directional movement or action, and when fully inserted the conduit Cis sealed against fluid pressure and is retained in position. The axialinsertion may be performed manually or by a tool or machine. By push toconnect is meant that the single action may be a simple axial movementor push along the longitudinal axis of the conduit C and that thissingle action is the only action needed to complete the mechanicalconnection between the conduit C and the fitting assembly 10. Nosubsequent or additional motion or action is needed to complete themechanical connection and fluid tight seal. In an exemplary embodiment,the single directional action or movement is an axial movement along alongitudinal axis of the conduit C. No other or additional or subsequentmanual or tool action or movement of the fitting assembly 10 componentsis needed to achieve conduit seal and retention. Thus, a single actionpush to connect fitting is distinguished from a traditional fittingassembly that typically is pulled-up or tightened to effect conduit gripand seal by relative movement of the fitting assembly components afterinsertion of the conduit; for example, a body and a nut that are joinedby a threaded mechanical connection and pulled-up by relative rotationof the body and nut, or by being clamped together without a threadedmechanical connection.

Herein, the terms axis or axial and derivative forms thereof refer to alongitudinal axis X along which a conduit C will be inserted andretained. Reference to radial and radial direction and derivative termsalso are relative to the X axis unless otherwise noted. In theillustrated embodiments, the axis X may be the central longitudinal axisof the conduit C which also may but need not correspond with or becoaxial with the central longitudinal axis of the fitting assembly 10.The conduit C may be any conduit that defines a flow path FP for systemfluid that is contained by the conduit C and the fitting 10. Theinventions and embodiments described herein are particularly suitablefor metal conduit such as metal pipe or tube, however, non-metalconduits may also be used as needed. The conduit C may have any range ofdiameter size, for example, 1/16th inch or less to 3 inches or greaterin diameter and may be in metric or fractional sizes. The conduit C mayalso have any range of wall thickness that allows for an axial insertioninto the fitting assembly 10.

The fitting assembly 10 may include two discrete sections orsubassemblies. In an embodiment, the fitting assembly 10 may include afirst fitting component or subassembly 12 and a second or fittingcomponent or subassembly 14. The first fitting component 12 and thesecond fitting component 14 may be joinable or mate together in anymanner suitable for the application or use of the fitting assembly 10.For example, the first fitting component 12 and the second fittingcomponent 14 may be joinable together using a threaded mechanicalconnection 16 (FIG. 2.) Many other mechanical connections mayalternatively be used, including but not limited to a clamped connectionor bolted connection or crimped connection, to name three examples, ornon-mechanical connections may be used, for example, a weldment.

Note that although the conduit C is shown in FIG. 3, the conduit C isnot considered to be part of the second fitting component 14.

FIGS. 1-3 illustrate the fitting assembly 10 in a fully assembledcondition, and further with the conduit C fully inserted or seated inthe fitting assembly 10. In this position, the conduit C is sealed andretained in position, especially against fluid pressure, although thefitting assembly 10 may be used in low or zero or negative pressureapplications.

With additional reference to FIGS. 4 and 5, the first fitting component12 may be realized as a body subassembly. The first fitting componentmay include a body 18 that is adapted to receive the conduit end C1.Although it is common to call the conduit receiving fitting component abody in fitting terminology, the first fitting component 12 may use afitting component other than what might be considered a fitting body.Also, the body 18 need not be a standalone component, but alternativelymay be formed as a cavity in a block, for example a manifold or a valvebody to name a couple of examples. Such body embodiments are commonlyknown in the art as a port or a ported fitting.

The second fitting component 14 may be realized as a nut subassembly.The second fitting component 14 may include a nut 20 through which theconduit end C1 passes into the body 18. Although it is common to callthe mating second fitting component 14 a nut in fitting terminology, thesecond fitting component 14 may be a fitting component other than whatmight be considered a fitting nut.

Although the exemplary embodiment illustrates a male threaded nut 20having male threads 22 and a female threaded body 18 having matingfemale threads 24, an alternative would be to have the nut 20 be femalethreaded and the body 18 be male threaded. And as noted above, the body18 and the nut 20 may be joinable by many different techniques,including a mechanical connection other than a threaded mechanicalconnection 16. Moreover, the body 18 and the nut 20 may be made of anysuitable material, for example stainless steel or other metal, or may bemade of non-metals, for example plastics or polymers or compositematerials or other suitable materials, as needed. For embodiments inwhich the conduit C is stainless steel or other metal, the body 12 andthe nut 14 are preferably made of metal and more preferably stainlesssteel alloy. Also, in additional embodiments, the body 12 and the nut 14are preferably all metal.

The nut 20 may include two or more pin holes 26 that can be used toreceive a tool that is used to drive the nut 20 into the body 18, forexample by rotation of the nut 20 relative to the body 18 about the axisX. It will be noted that the axial dimension of the nut 20 may beselected so that the outboard end 20 a of the nut 20 appears flush withthe outboard end surface 18 a of the body 18, when the nut 20 is fullytightened, but this flush arrangement is optional. The nut 20 may alsoinclude a flange 28 having an end surface 30 that engages a firstcounterbore surface 32 in the body 18. This engagement between the nutend surface 30 and the body first counterbore surface 32 provides apositive stop to further tightening of the nut 20 relative to the body18 thereby preventing over-tightening. As best viewed in FIG. 1, thebody 18 may include wrench flats 34, for example hex flats, to assist intightening the body 18 and the nut 20 together when a threadedmechanical connection is used.

The body 18 may include an optional second counterbore or socket 36 thatis adapted to receive the conduit end C1. The second counterbore 36 ofthe body 18 may be used as a positive stop during insertion of theconduit C into the fitting assembly 10 so that the assembler can sensethat the conduit C is preferably fully inserted and seated against thecounterbore 36 shoulder (see FIG. 2.) However, many other techniques mayalternatively be used to control or delimit the axial distance that theconduit C is inserted into the fitting assembly 10. The body 18 mayinclude a flow passage or bore 38 for fluid that passes through theconduit C and the fitting assembly 10. Alternatively, the body 18 may beformed as a cap or plug with the flow passage 38 omitted.

The body 18 retains a seal device 40 that establishes a fluid tight sealagainst fluid pressure for the outer surface of the conduit C and alsoto seal the body 18. The body 18 may include a third counterbore 42 thatdelimits a socket that receives the seal device 40, and as such the body18 and the seal device 40 form the first fitting component 12. The thirdcounterbore 42 helps to retain the seal device 40 in position when theconduit C is inserted into the fitting assembly 10. The seal device 40may comprise a single seal member or alternatively multiple seal membersas shown in FIGS. 2, 3 and 4. For example, the seal device 40 mayinclude a primary seal member 44 such as, for example, an elastomerico-ring style seal. Many different primary seal member designs andmaterials may alternatively be used, including but not limited to ahalogen polymer (for example, PTFE), carbon (for example, expandedgraphite), soft metal (for example, silver), spring metal (for example,X750, 17-4PH.) The seal device 40 may further include one or moreoptional backing rings 46, 48 which may be used as needed to help reduceextrusion of the softer primary seal 44 under pressure. The backingrings 46, 48 may be made of a harder plastic material, for example PTFEor PEEK as compared to the primary seal member 44. An optional gland 50,which may be metal or other suitable material as needed, may be used toreduce or prevent damage to the seal device 40 due to contact with aretainer (described below) and also to help retain the seal device 40 inposition as part of the first fitting component 12. The primary sealmember 44 provides a fluid tight seal for the fitting 10 by beingcompressed against the outer surface of the conduit C and one or moresurfaces of the third counterbore 42 or socket in which the seal member44 is disposed within the body 18. The seal device 44 therefore providesa primary body seal to contain fluid within the fitting 10 so as toprevent fluid that is in the conduit C from escaping to the ambient orsurrounding environment. The body seal and the conduit seal are effectedwhen the conduit C has been inserted axially into the body 12sufficiently so as to pass through the primary seal member 44.

The second fitting component 14 as noted may include the nut 20, andalso a retainer 52. The retainer 52 operates to grip and lock orotherwise retain the conduit C with the nut 20 when the conduit C hasbeen sufficiently inserted axially into the fitting assembly 10 so as toengage the retainer 52. It will be noted from the following descriptionthat the retainer 52 can grip and retain the conduit C with the nut 20at an axial position that is less than a full insertion used to achieveconduit seal by the seal device 40. The conduit C can optionally even beretained with the nut 20 when the nut 20 has not been assembled to thebody 18.

In an embodiment (see FIG. 5,) the retainer 52 may be a subassemblycomprising a ball cage 54, a conduit gripping member 56 and a biasingmember 58. Although the ball cage 54 and the conduit gripping member 56are shown as two distinct parts, alternatively other retainer designsmay be used that would integrate this functionality into a single part,further optionally including the functionality of the biasing member 58.The conduit gripping member 56 may be realized in the form of one ormore preferably spherical balls 56, although other conduit grippingmember designs may alternatively be used as needed. In FIG. 5 theconduit gripping member 56 appears to be displaced out of contact withthe ball cage 54 even though there is no conduit it FIG. 5. This is donefor clarity and understanding of the structure. Those skilled in the artwill readily understand that when the conduit C is not positioned in theretainer 52 the balls 56 drop partially into the ball cavities (64) asexplained further below.

FIGS. 4 and 5 thus illustrate an embodiment in which the first fittingcomponent 12 is a standalone subassembly and the second fittingcomponent 14 is also a standalone subassembly. The first fittingcomponent 12 and the second fitting component 14 when assembled orjoined together thus provide or thin′ the fitting assembly 10. Thefitting assembly 10 therefore is a simple two part assembly which cansimplify assembly and use in the field. The first fitting component 12and the second fitting component 14 may be assembled together at themanufacturer, a distributor or by the end user. After the first fittingcomponent 12 and the second fitting component 14 have been assembledtogether, the fitting assembly 10 provides a complete single action pushto connect fitting by which all that is needed to make a mechanicalconnection with a conduit end, as well as seal the conduit end againstfluid pressure, is to push the conduit end into the fitting assembly 10until the conduit end preferably bottoms against the second counterbore36 or alternatively is axially inserted into the fitting assembly sothat the seal device 40 engages with the outer surface of the conduit C.The conduit C may be inserted manually or alternatively by use of a toolor a machine or other convenient means. Insertion of the conduit C intothe fitting assembly 10 makes the mechanical connection and the fluidtight seal between the conduit C and the fitting assembly 10 without anyrequired subsequent or further or additional action or motion.

The ball cage 54 may be adapted to move or shift axially within acentral bore 60 of the nut 20. The ball cage 54 includes a through bore62 that preferably is at least cylindrical partially admits insertion ofthe conduit C into the fitting assembly 10 (FIG. 2) with a preferablyclose fit. An inward end portion 54 b of the ball cage 54 includes oneor more ball cavities 64 that position or trap the balls 56 within apreferably tapered wall cavity 66 of the nut 20. The tapered wall cavity66 of the nut 20 is delimited by a tapered wall 66 a that preferably isfrusto-conical, but alternatively other geometric shapes and forms maybe used as needed. Note that in FIG. 5 as well as FIGS. 2 and 8 forclarity we only show one ball 56, but in practice there may be a ball 56in each ball cavity 64 or fewer balls 56 may be used, althoughpreferably there will be at least three balls used. Each ball cavity 64may include a beveled or shaped ball cavity wall or surface 68 that maybe sized and beveled or shaped to prevent the associated ball 56 fromfalling through the ball cavity 64. However, each ball cavity 64 ispreferably sized so that at least a portion of each ball 56 protrudesthrough the associated ball cavity 64 so as to make contact with theconduit C outer surface (see FIGS. 2 and 6).

The balls 56 may be made of any suitable material as needed, preferablymade of metal especially when used with a metal conduit C, and morepreferably made of stainless steel.

The central bore 60 of the nut 20 may include a radially inwardprojecting rib 70 and the outboard end 54 a of the ball cage 54 mayinclude a radially outwardly projecting flange 72 that presents an innersurface 72 a that faces towards the rib 70. The flange 72 and the rib 70along with the central bore 60 of the nut 20 define a slot 74 thatreceives the biasing member 58. The biasing member 58 may be realized inthe form of a coiled spring as shown, however, many other types ofbiasing members may alternatively be used. The spring or biasing member58 is compressed in the slot 74 so as to apply an outwardly directedaxial force on the ball cage 54. By outwardly is meant in an axialdirection away from the conduit end C1. The ball cage 54 is able to moveor shift axially although the movement or shift may be slight andperhaps imperceptible by visual or tactile feedback. The axial biasproduced by the spring 58 pulls the balls 56 that sit in the ballcavities 64 in towards the radially narrower portion of the tapered wallcavity 66 such that the balls 56 engage the tapered wall 66 a and aretrapped against the tapered wall 66 a because of the limited radialmovement permitted by the ball cavities 64. The trapped balls 56 thusalso prevent the spring 58 from pushing the ball cage 54 out through thenut central bore 60.

It will be noted that the amount of axial movement or shift of the ballcage 54 will be a function of a number of design factors including thesize of the balls 56 relative to the size of the tapered wall cavity 66.The biasing member 58 thus serves to maintain the retainer 52 with thenut 20 as a complete subassembly of the second fitting component 14.Also note that in FIG. 2 (as well FIG. 8) the spherical ball 56 is showncentered in the respective ball cavity 64, but this is an artifact ofthe drawing model. In practice, the biasing member 58 axially biases theball cage 54 outwardly so as to wedge the balls 56 between the taperedwall 66 a and the outer surface of the conduit C. The balls 56 thereforewould be in contact with the forward or inward portion of the ballcavity wall or surface 68 that delimits the ball cavity 64.

With reference to FIGS. 6 and 7, as the conduit C is inserted into thefitting assembly 10, the conduit end C1 will contact or engage the balls56 which partially protrude through the ball cavities 64. The initialcontact of the conduit end C1 with the balls 56 is shown in FIG. 7. Asthe conduit end C1 is further inserted, the balls 56 and the ball cage54 are moved or shifted axially inward against the force of the spring58 so that the balls 56 can be radially displaced further (by a rollingaction of the balls 56 on the outer surface of the conduit C) into theball cavities 64 and the tapered wall cavity 66 so as to allow theconduit end C1 to be fully inserted into the second counterbore 36 ofthe body 18. This movement occurs due to frictional engagement betweenthe balls 56 and the conduit end C1 outer surface. This same frictionalengagement helps to prevent the conduit C from simply being pulled outonce it has engaged with the balls 56. The conduit end C1 may include achamfer (84 in FIG. 2) to facilitate initial contact with the balls 56.The amount of axial and radial shift or movement of the balls 56 maytypically be rather small and just enough so as to allow the conduit endto be inserted fully. All that is needed is enough movement to releaseload of the balls 56 against the conduit so that the conduit freelyslides into the fitting 10. Conduit insertion may be done by anyconvenient means or technique, including but not limited to hand-heldmanual insertion, use of a tool to assist with manual insertion ormachine insertion.

When the conduit C has been fully inserted into the second counterbore36 of the body 18 as represented in FIG. 2, the retainer 52 has an axialposition within the nut 14 such that the balls 56 are in contact withthe conduit C and the tapered wall 66 a due to the bias of the spring58. We refer to this axial position of the retainer 52 to be the firstaxial position within or relative to the fitting assembly 10 and that isthe axial position for gripping and retaining the conduit C in thefitting assembly 10 to constrain the conduit C from axial withdrawalfrom the conduit fitting 10. Thus, the balls 56 are wedged and trappedand cannot move radially or axially, thereby exerting a retaining forceand tight grip on the conduit C. The biasing member 58 maintains theballs 56 in contact with the tapered wall 66 a and the conduit C outersurface, thereby applying a retaining force or load against the conduitC to resist axial withdrawal of the conduit C from the fitting 10. Theballs 56 resist axial withdrawal of the conduit C from the ball cage 54and the more force that is applied to the conduit C to pull it out thestronger is the gripping force and retention due to the wedging actionof the balls 56 trapped between the conduit C outer surface and thetapered wall 66 a. The friction and radial load between the balls 56 andthe conduit outer surface prevents axial movement of the conduit backout of the fitting 10 and this load will increase if an axial force isapplied to the conduit C to try to pull the conduit C back out of thefitting 10. Note that the conduit C is trapped in this position in theball cage 54 even if the nut 14 is not installed in the body 18(although in that circumstance the conduit can be pushed forward but notpulled rearward, and the spring 58 will prevent the conduit C and theball cage 54 from falling apart.)

Note also that fluid pressure, from system or working fluid in theconduit C, acting on the seal device 40 (with or without the optionalgland 50) and/or an end face of the conduit end C1 will tend to increaseaxial forces against either the ball cage 54 or the conduit C or bothtowards the reduced sized portion of the tapered wall cavity 66. Theseaxial forces due to fluid pressure will tend to further increase thecompression of the balls 56 against the tapered wall 66 a, thus alsoincreasing the grip and retention of the conduit C by the balls 56. Itis contemplated that the balls 56 may comprise a harder material thanthe conduit C so that the balls 56 may actually indent into the outersurface of the conduit C, further increasing resistance to the conduit Cbeing axially withdrawn or forced out of the fitting 10.

However, the conduit C can be easily withdrawn or pulled out of theretainer 52, for example the ball cage 54, by simply applying an axiallyinward force against the ball cage 54 and the biasing force of thespring 58, for example, by pushing against the flange 72 such as byapplying a force against the outboard end 54 a of the ball cage. Bypushing on the ball cage 54 against the force of the spring 58, the ballcage 54 can be moved or shifted axially forward (as viewed in FIG. 2) toanother axial position within the fitting assembly 10 at which thecompression on the trapped balls 56 against the conduit C is reducedenough so that the conduit C can be axially withdrawn or removed fromthe fitting assembly 10. We refer to this axial position of the retainer52, that is sufficient to reduce the compression on the trapped balls 56to allow withdrawal of the conduit C, as the second axial position ofthe retainer 52 within the fitting assembly 10. Again, this movement orshift of the retainer 52 may be slight so as to release the stress onthe balls 56. Thus, the retaining force of the balls 56 against theconduit C is lessened and the conduit C will easily slide back out ofthe fitting assembly 10. The fitting 10 design also allows of repeatedre-use, also known as remake, of the fitting, either with the sameconduit or a different conduit.

An axially inward force may be applied against the flange 72 of the ballcage 54 either manually such as with fingers or optionally with a tool(not shown.) From FIG. 2 it will be noted that an embodiment of the ballcage 54 has the outboard end 54 a axially recessed in the nut 20. If therecess is deep, a tool might be used to push on the ball cage 54.Alternatively, the recess may be shallow enough that fingers or a toolcould be used to push on the outboard end 54 a. As another alternative,the ball cage 54 may be axially sized so as to position the outboard end54 a either flush, about flush or slightly outside of the nut 20, in anycase making it easier to contact the ball cage 54 with a tool or fingersto displace the ball cage 54 so that the conduit C can be withdrawn.Preferably, fluid pressure will be reduced to ambient pressure beforethe retainer 52 is acted on to allow the conduit C to be withdrawn.

Note further that although preferably the conduit gripping member 56,whether in the form of one or more spherical balls or other form,becomes wedged or trapped between the conduit C outer surface and apreferably tapered surface 66 a, other surface geometries or additionalcomponents may be used that compress the conduit gripping device 56against the conduit C to constrain axial withdrawal of the conduit C. Itis preferred, whatever technique or structure is used to constrain theconduit C in the fitting assembly 10, that there be a first position anda second position, that can be selected from outside the assembledfitting 10 (for example in the exemplary embodiment pushing the retainer52 to the second axial position), to release the conduit C forwithdrawal from the fitting assembly 10, without necessarily having toloosen or separate the first fitting component 12 and the second fittingcomponent 14.

Note from FIG. 2 that when the ball cage 54 is pushed inward against theforce of the spring 58, the distal end of the ball cage 54 could contactthe optional gland 50, so that gland 50 helps protect against damage tothe seal device 40 in such an event.

An outwardly extending portion 76 of the ball cage 54 inner diameterthrough bore 62 optionally may be outwardly tapered so as not to applystress to the conduit C (which can cause fretting) when possible systemvibration may impart rotary flex or oscillation of the conduit C. Thetaper angle α and the length of the tapered portion 76 need only belarge enough to reduce or prevent stress being applied to the conduit Cby the ball cage 54. This will cause the stress from conduit oscillationor vibration to be concentrated more at the balls 56.

The ball cavities 64 and the balls 56 may be evenly spacedcircumferentially from each other in the ball cage 54 so as to furtherreduce potential damage to the conduit caused by vibration andoscillation of the conduit. An even or uneven number of balls 56 may beused. A benefit of an uneven number of balls 56 is that no two ballswill be diametrically opposed to each other when the balls 56 are inposition in the ball cage 54.

With reference to FIGS. 2 and 5, the body 18 includes a partiallythreaded cylindrical bore 78 in which the female threads 24 (FIG. 4) maybe formed. This bore 78 may include a fourth counterbore 80 with atapered shoulder 82. This tapered shoulder 82 may be used to provideadditional space for movement of the balls 56 when the ball cage 54 isaxially shifted to allow a retained conduit C to be removed. Note alsothat the conduit end C1 may include the chamfer 84 to reduce or preventdamage to the seal device 40 when the conduit C is inserted into thefitting assembly 10.

Further note that preferably but not necessarily the seal device 40 isaxially disposed between the conduit end C1, which is the fluid pressurehead, and the retainer 52, with the conduit C being inserted from theretainer side of the fitting assembly 10. In other words, duringassembly the conduit C is inserted into the fitting assembly 10preferably from the axially outward side or end of the retainer 52 (fromthe left as viewed in FIGS. 2, 6 and 7) and passes through the axiallyopposite side or end of the retainer 52 before the conduit end C1engages with or passes through the seal device 40. The conduit thereforeis inserted into the fitting assembly 10 preferably from the biasingmember side of the retainer 52. This allows easier assembly andretention of the seal device 40 with the fitting body 18 as asubassembly and also helps reduce or prevent system fluid wetting of theretainer 52, for example, the spring 58.

FIGS. 8 and 9 illustrate another embodiment of a single action push toconnect conduit fitting 10′. In this embodiment, most of the componentsand parts of the fitting 10′ may be but need not be the same as theembodiment of FIGS. 1-7 above. Therefore, like reference numerals areused for like parts and the description of the parts need not berepeated. Note again that although the conduit C is shown in FIG. 9, theconduit C is not considered to be part of the second fitting component14.

The embodiment of FIGS. 8 and 9 differs from the embodiments describedabove in the design of the retainer 90. In an embodiment, the retainer90 may be a subassembly comprising a ball cage 92, a conduit grippingmember 94 and the biasing member 58. Although the ball cage 92 and theconduit gripping member 94 are shown as two distinct parts,alternatively other retainer designs may be used that would integratethis functionality into a single part, further optionally including thefunctionality of the biasing member 58. The conduit gripping member 94may be realized in the form of a first set of one or more preferablyspherical balls 94, although other conduit gripping member designs mayalternatively be used as needed. The ball cage 92 may be adapted to moveor shift axially within a central bore 60 of the nut 20. The ball cage92 includes a through bore 96 that admits insertion of the conduit Cinto the fitting assembly 10′. An inward end portion 92 b of the ballcage 92 includes one or more ball cavities 98 that position or trap theballs 94 within a preferably tapered wall cavity 66 of the nut 20. Notethat in FIGS. 8 and 9 for clarity we only show one conduit grippingmember or ball 94, but in practice there may be a ball 94 in each ballcavity 98 or fewer balls 94 may be used, although preferably there willbe at least three balls used. Each ball cavity 98 may include a beveledor shaped ball cavity wall 100 that may be sized and beveled or shapedto prevent the associated ball 94 from falling through the ball cavity98. However, each ball cavity 98 is preferably sized so that at least aportion of each ball 94 protrudes through the associated ball cavity 98so as to make contact with the conduit C outer surface.

The central bore 60 of the nut 20 may include a radially inwardprojecting rib 70 and the outboard end 92 a of the ball cage 92 mayinclude a radially outwardly projecting flange 102 that presents aninner surface 102 a that faces towards the rib 70. The flange 102 andthe rib 70 along with the central bore 60 of the nut 20 define a slot 74that receives the biasing member 58. The biasing member 58 may berealized in the form of a coiled spring as shown, however, many othertypes of biasing members may alternatively be used. The spring orbiasing member 58 is compressed in the slot 74 so as to apply anoutwardly directed axial force on the ball cage 92. By outwardly ismeant in an axial direction away from the conduit end C1. The ball cage92 is able to move or shift axially although the movement or shift maybe slight and perhaps imperceptible by visual or tactile feedback. Theaxial bias produced by the spring 58 pulls the bills 94 that sit in theball cavities 98 in towards the radially narrower portion of the taperedwall cavity 66 such that the balls 94 engage the tapered wall 66 a andare trapped against the tapered wall 66 a because of the limited radialmovement permitted by the ball cavities 98. The trapped balls 94 thusalso prevent the spring 58 from pushing the ball cage 92 out through thenut central bore 60.

It will be noted that the amount of axial movement or shift of the ballcage 92 will be a function of a number of design factors including thesize of the balls 94 relative to the size of the tapered wall cavity 66.The biasing member 58 thus serves to maintain the retainer 90 with thenut 20 as a complete subassembly of the second fitting component 14.

The retainer 90 further includes a second set of preferably sphericalballs 104 although other shapes may be used as needed. The second set ofspherical balls 104 are preferably smaller in size than the first set ofspherical balls 94. The ball cage 92 further includes a second set ofball cavities 106. The second set of ball cavities 106 and the balls 104may be evenly spaced circumferentially from each other in the ball cage92 so as to reduce potential damage to the conduit C caused by vibrationand oscillation of the conduit. As with the first set of balls 94 thatare used for the conduit gripping device, an even or uneven number ofballs 104 may be used. A benefit of an uneven number of balls 104 isthat no two balls will be diametrically opposed to each other when theballs 104 are in position in the ball cage 92.

The second set of balls 104 are preferably spaced axially outwardly fromthe first set of balls 94. The idea is to have the second set of balls104 also be trapped between the tapered wall 66 a and the conduit C soas to add rigidity and stiffness to the support of the conduit C,somewhat akin to using two bearings spaced apart to support a rotatingshaft. By having the second ball set 104 smaller in diameter than thefirst ball set 94, the same tapered wall 66 cavity may be used to retainthe ball sets and still have the second ball set 104 axially spaced fromthe first ball set 94. An alternative embodiment may use twodiscontinuous tapered surfaces for the two ball sets, or otherstructures by which the second ball set 104 is trapped between the nut20 and the conduit C.

The amount of axial separation provided between the first ball set 94and the second ball set 104 will be based on various factors includingbut not limited to the loads that are expected on the conduit C and theamount of flex and vibration to which the conduit C may be exposed inuse. The second ball set 104 is preferably axially spaced outwardly fromthe first ball set 94, in a direction away from the conduit end C1.Thus, the second ball set 104 helps to isolate the conduit grippingfirst ball set 94 from conduit vibration and rotary flex and otherenvironmental stresses that the conduit C may experience during use. Inorder to help assure that the second ball set 104 makes contact with thetapered wall 66 a and the conduit C when the first ball set 94 does thesame, the tolerances may be chosen so that during assembly and under thebiasing influence of the biasing member 58 on the ball cage 92, thefirst ball set 94 contacts the tapered wall 66 a first or before thesecond ball set 104 would make such contact. The first ball set 94indents slightly into the outer surface of the conduit C, which producesenough axial shift of the ball cage 92 to allow the second ball set 104to also make contact with the tapered wall 66 a.

As an example, for conduit C, nut 20 and balls 94 made of 316L stainlesssteel, and quarter-inch nominal outer diameter conduit and nominal wallthickness of 0.035 in., the first ball set 94 may indent into theconduit surface in the range of approximately 0.003 in to 0.004 in andup to approximately 0.008 in. These numbers and ranges are exemplary ofcourse because the actual numbers will be adjusted based on materialsused for the retainer parts and the conduit, conduit wall thickness,diameters and so on. The conduit gripping member 56 in the firstembodiment (FIGS. 1-7) and the conduit gripping member 94 of the secondembodiment (FIGS. 8 and 9) may use this indentation feature into theconduit C outer surface to enhance the ability of the retainer 52/90 togrip and hold the conduit C over and above the friction forces that alsowork to retain the conduit C, advantageously when the conduit C is underpressure. For embodiments that use two ball sets, the second ball set104 may also contribute to conduit grip by also indenting into theconduit C outer surface, although this is more likely to be the caseunder elevated pressures. Conduit grip by the second ball set 104 may bea benefit realized in some designs and applications, but the first ballset 94 preferably is designed to provide sufficient and primary conduitgrip and retention, while the second ball set 104 preferably is designedto provide isolation of conduit vibration and flex from the first ballset 94.

From FIG. 9 it will be noted that each ball cavity 98 may include anaxially extending relief or groove 108. During assembly of the retainer90 into the nut 20, due to the limited axial movement of the ball cage92 resulting from the flange 72 contacting the rib 70, it may be in somecases that the ball cage 92 can only extend just far enough to partiallyexpose the ball cavities 98 to allow the balls 94 to be positioned intothe ball cavities 98. The relief or groove 108 allows sufficient room orgap between the tapered wall 66 a and the ball cage 92 to allow thesecond ball set 104 to be assembled into the ball cage 92.

Assembly and operation of the single action push to connect fitting 10′of the alternative embodiment of FIGS. 8 and 9 may be though need not bethe same as the first fitting 10 embodiment of FIGS. 1-7 and thereforethe description need not be repeated.

The inventive aspects and concepts have been described with reference tothe exemplary embodiments. Modification and alterations will occur toothers upon a reading and understanding of this specification. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentsthereof.

We claim:
 1. A fitting assembly for conduit with the conduit having alongitudinal axis, comprising: a fitting body that is adapted to receivea conduit end; a seal device disposed in said fitting body that sealsagainst an outer surface of a conduit when the conduit is inserted intosaid fitting body; a fitting nut that is adapted to be joined to saidfitting body; a retainer at least partially disposed within said fittingnut, the retainer including an outboard end portion and an inward endportion, wherein said retainer comprising a conduit gripping member thatgrips an outer surface of the conduit when said retainer is in a firstaxial position in said fitting assembly, said conduit gripping memberreleasing grip of the conduit when said retainer is in a second axialposition in said fitting assembly that is different from said firstaxial position; and a biasing member that applies an outward biasingforce to the outboard end portion of the retainer; wherein the inwardend portion of the retainer is engageable with the seal device, suchthat under fluid pressure the seal device applies an axial force againstthe inward end portion of the retainer toward gripping engagement withthe conduit.
 2. The fitting assembly of claim 1 wherein said seal devicecomprises elastomeric material.
 3. The fitting assembly of claim 1wherein said conduit gripping member comprises one or more spheres orballs.
 4. The fitting assembly of claim 3 wherein said retainercomprises a ball cage that positions said conduit gripping member insaid fitting nut.
 5. The fitting assembly of claim 1 wherein saidbiasing member comprises a coil spring, a wave spring, or a Bellevillespring.
 6. The fitting assembly of claim 1 wherein said fitting nutcomprises a tapered surface that engages said conduit gripping memberwhen said retainer is in said first axial position.
 7. The fittingassembly of claim 1 wherein said retainer comprises a cylindricalthrough bore that admits insertion of the conduit.
 8. The fittingassembly of claim 7 wherein said cylindrical through bore is delimitedby a wall comprising a cylindrical portion and a tapered portion.
 9. Thefitting assembly of claim 1 wherein said retainer applies a retainingforce to the conduit to constrain axial movement of the conduit, whereinwhen the fitting assembly is under fluid pressure said retaining forceincreases.
 10. The fitting assembly of claim 1 wherein said seal deviceis axially positioned at a first side of said retainer that is axiallyopposite a second side of said retainer, wherein the conduit is insertedinto the fitting assembly through said second side of said retainer. 11.A fitting assembly for conduit with a longitudinal axis, comprising: afirst fitting component that is adapted to receive a conduit end; a sealdevice disposed in said first fitting component that seals against anouter surface of a conduit when the conduit is inserted into the firstfitting component; a second fitting component that is adapted to bejoined to said first fitting component, the second fitting componentcomprising a retainer for gripping the conduit when the conduit isinserted into said second fitting component, the retainer including anoutboard end portion and an inward end portion; and a biasing memberthat applies an outward biasing force to the outboard end portion of theretainer wherein said retainer applies a retaining force to an outersurface of the conduit when said retainer is in a first axial positionin said fitting assembly, said retainer releasing said retaining forcewhen said retainer is in a second axial position in said fittingassembly that is different from said first axial position; wherein theinward end portion of the retainer is engageable with the seal device,such that under fluid pressure the seal device applies a fluid pressuredriven axial force against the inward end portion of the retainer towardgripping engagement with the conduit.
 12. The fitting assembly of claim11 wherein said retainer comprises a ball cage and one or more conduitgripping balls and said seal device comprises an o-ring.
 13. The fittingassembly of claim 11 wherein said seal device comprises elastomericmaterial.
 14. The fitting assembly of claim 11 wherein said retainercomprises a conduit gripping member.
 15. The fitting assembly of claim14 wherein said conduit gripping member comprises one or more spheres orballs.
 16. The fitting assembly of claim 14 wherein said retainercomprises a ball cage that positions said conduit gripping member insaid second fitting component.
 17. The fitting assembly of claim 11wherein said biasing member comprises a coil spring, a wave spring, or aBelleville spring.
 18. The fitting assembly of claim 14 wherein saidsecond fitting component comprises a tapered surface that engages saidconduit gripping member when said retainer is in said first axialposition.
 19. The fitting assembly of claim 11 wherein said retainercomprises a cylindrical through bore that admits insertion of theconduit.
 20. The fitting assembly of claim 19 wherein said cylindricalthrough bore is delimited by a wall comprising a cylindrical portion anda tapered portion.